The current state-of-the-art in depleted uranium processing requires that DUF6 tailings be converted into DUF4 (depleted uranium tetrafluoride), which can be processed into metallic inorganic fluoride gases, like GeF4, SiF4, and BF3. Pearlhill Technologies has just proved it is feasible to develop nonmetallic inorganic fluorides from uranium tetrafluoride (NIFUT) to produce sulfur tetrafluoride (SF4) gas and triuranium octaoxide (U3O8) from depleted UF4. Producing SF4 opens the door to a whole range of metallic inorganic fluoride gases with established commercial markets. This project will contribute to uranium tailing management in the Excess Uranium Inventory Management Plan of the United States Department of Energy, by achieving viable large scale fluorine recovery for civilian market.
Currently, conversion processes involve either (i) hydrolysis of DUF6 to produce U3O8, along with anhydrous hydrogen fluoride (HF); or (ii) using the fluorine extraction process (FEP) to produce commercially valuable metal fluorides, such as BF3, GeF4, SiF4, and U3O8. This technology (i) is economically unviable; and the FEP technology for production of metallic fluorides, such as BF3, GeF4, and SiF4, appears to be viable for production of very expensive high purity gas product grades that are priced to pay for the high cost of production. While the FEP is profitable for production of expensive, limited-volume specialty products like GeF4, it is still to be proven viable for bulk gases BF3, and SiF4, respectively.
Meanwhile, DOE has 700,000 metric tons of UF6 that can be recovered into useful marketable fluorinated products. United States Enrichment Corporation (USEC), Louisiana Energy Services (LES), AREVA Inc., and General Electric (GE) have all either announced plans to build, or are building new nuclear fuel enrichment facilities in the United States. When these facilities are completed, at their initial stated capacity, they will produce approximately 60 million pounds of DUF6 tails each year. DUF6 cannot be disposed of directly, but must be converted into disposable waste forms. There are very few facilities in the U.S. today that can convert depleted DUF6 tails. This patent presents the most effective and economically viable alternative technology for fluoride recovery from UF6.